1. Field of the Invention
This invention relates to a method for forming small diameter holes in polyimide/KEVLAR.RTM. substrates using hot concentrated sulfuric acid to form these small diameter openings and then honing, as necessary, to smooth uneven edges of the openings.
2. Description of the Related Art
The use of solvents for forming small diameter openings in polyimide substrates is disclosed in U.S. patent application Ser. No. 806,874, filed Dec. 9, 1985, now U.S. Pat. No. 4,639,290, and entitled, "Methods for Selectively Removing Adhesives from Polyimide Substrates." While working well for their intended purpose, the methods disclosed there are, however, ineffective in forming small diameter openings in polyimide/KEVLAR.RTM. substrates.